Phantom Falls
by FrostyPines
Summary: Something strange is going on in Gravity Falls, or so Danny Fenton thinks. He's on a mission to figure out what's happening and how to stop it, but things don't go as planned.
1. Chapter 1

Danny, Sam, and Tucker sat around the newest piece of Fenton equipment. Having branched out some, the Fenton Scanner located traces of supernatural activity all over the country.

"Looks like there's a few major hotspots." Sam was saying. She glared at Tucker, who was absorbed in his new iPad. "Tucker, would you pay attention?"

"I am. Supernatural hotspots. Continue." He didn't even glance up. Danny chuckled softly.

Sam rolled her eyes. "Anyway, the ghosts in Amity Park are on a low down right now, so Danny should be free to go investigate some other places."

"Wait, leave Amity Park?" Danny sat up straight. "But what if-?"

"Danny, we can handle it. Tucker and I will stay here. Who knows what things might be going on elsewhere? These places might need some help." Sam looked at him significantly. Danny knew what she meant. Recently, they had been getting word that strange things were happening both in the Ghost Zone and on Earth. Upheavals of mysterious energy and people going missing. They had to do what they could to help. Danny would have thought that maybe Vlad was behind it, except that his nemesis had vanished three days ago, leaving no trace. He never disappeared for this long, and anyway whenever he went on a "business trip" Danny found him up to no good and stopped him. Usually.

The other ghosts that normally haunted Amity Park were keeping their distance, preferring to stay in the Ghost Zone, which had to mean that something was happening such that they did not want to venture into the mortal world. And according to the Fenton Scanner, new places were reporting high levels of supernatural energy.

"So," Sam continued, "looks like some major contact points are a place in the Southwest called Night Vale, and a town in Oregon called Gravity Falls. Night Vale seems to be fairly isolated, and it's giving off readings that seem… less important. Like it exists outside of the normal world. So I recommend Danny scouts out Gravity Falls."

"Okay. Well, that's great. But how am I going to get away with going across the country with my parents watching my every move?" Danny asked dubiously.

"Simple!" exclaimed Tucker. "You'll just go to my house!" Both Danny and Sam gave him confused looks, so he smiled and continued. "Its summer break, so just tell your parents that you're going to sleep over at my house for a couple of days!"

"But what if they talk to your parents?" Danny asked dubiously.

"My parents are leaving on vacation and won't even be here." Tucker said confidently.

"And we can stea- I mean borrow," Tucker caught himself as both Danny and Sam gave him disapproving looks, "some of your parents' tech. I'll even trick out your phone and stuff."

Danny took a deep breath. "Okay, then. Looks like I'm headed to Gravity Falls."


	2. Chapter 2

Dipper sat in a booth at Greasy's Diner with Mabel, Grunkle Stan and Soos, enjoying a split plate of pancakes. Lazy Susan came over to the table, asking if they needed anything else.

"You know what? Get us some more pancakes. I'm feeling generous today." Grunkle Stan said, leaning back against the seat.

"Wow, thanks Grunkle Stan!" Mabel said, sopping up some syrup with her last bite of pancake.

Dipper suspected that Stan was only being so nice because Soos had eaten half the pancakes by himself and Stan was still hungry.

"So, you dudes got anything exciting planned for today?" Soos asked.

"Mabel and I were going to go explore the forest some more." Dipper said.

"Aww, bro, we do that all the time. We should go-" Mabel stopped talking abruptly. She was staring at the door into the diner.

A boy had just walked in. He looked like he was around 16, with jet black hair and bright blue eyes. He was carrying a large pack on his back like he was traveling, and looked around the diner with curiosity.

"Razzle dazzle!" Mabel exclaimed. "Check out that guy!"

Dipper turned around in his seat, then rolled his eyes. "Seriously, Mabel?"

She was staring at the boy with a dazed smile on her face. "I'm going to go talk to him!"

"Mabel-" Dipper tried to protest, but Mabel was already halfway across the diner.

"Let her give it a shot." Stan said, waving Dipper off. "This should be good."

"And romantic!" said Soos enthusiastically. Dipper gave him a strange look, but decided to ignore the comment.

Mabel rushed over to Tall Darkish and Handsome. He sat down at a booth close to the door. She slid in across from him.

"Hey…" She said, fluttering her eyelashes. "I'm Mabel. What brings you this lovely diner today?

"Uh, hi." The stranger looked a bit apprehensive. "I'm Danny. Just um, checking out the area. Passing through, you know."

"Ooh! Where you going?"

"Nowhere in particular, really." Danny tapped his chin thoughtfully. "Hey, you wouldn't mind showing me around a bit, would you? I'm planning on staying here for a few days."

Mabel gasped. "Sure I will!"

Dipper, who had heard this conversation from a few tables away, decided he better not let his sister go roaming the town with this guy she had just met. He got up and walked over to their booth. "Hey, sorry about my sister. She can be a little… enthusiastic."

"Oh, no worries." Danny said. "She's your sister? What's your name?"

"I'm Dipper. And we would love to show you around, but-"

"Dude, no one knows the weird stuff in this town like these two." Soos had come up behind Dipper silently.

Dipper jumped. "Don't scare him off when he just got here, Soos!"

Danny laughed. "It'll take more than some weird sights to scare me off. I actually came here to check out the uh, stuff like that."

"Really?" Stan had appeared behind Dipper faster than the speed of light. "Than what you need is to visit the world-famous Mystery Shack!"

"Mystery Shack?" Danny said dubiously.

"Come on, we'll take you there!" Stan said excitedly.

"What?" Danny tried halfheartedly to protest but the Pines were practically dragging him out the door.


	3. Chapter 3

Danny stood outside the questionable shack. He hadn't anticipated his sudden induction into a local family, but it might make his job easier. If Mabel didn't lock him in her closet for safekeeping, that is.

"Allow me to show you around the amazing Mystery Shack!" Stan said dramatically.

"Um, were you wearing that eyepatch earlier?" Danny asked.

Stan ignored him. "If you'll follow me inside, the first thing you're gonna see is the incredible Sascrotch!"

Danny endured the ridiculous tour, but saw absolutely nothing that looked genuine or posed an actual threat.

"Sorry about him." Dipper said after Danny finished with the tour and was looking around the gift shop. "I'm guessing that's not exactly what you meant when you said you wanted to see weird stuff."

Danny laughed. "Yeah, not quite."

"Hey, Danny," Mabel said from her perch atop the counter, "Why don't you crash here? You said you were staying a few days."

Danny was startled. "Oh, I was going to look for a hotel…"

"I don't think that there are any hotels in Gravity Falls." Dipper said pensively.

"That's weird..." Danny said. He shivered a bit, and a wisp of misty breath escaped his mouth, even though it was close to 80 degrees. Dipper was the only one who noticed.

"I'm sure Soos wouldn't mind lending you his break room." Mabel said excitedly.

"Boom. Done." Soos said, passing behind the trio while sweeping.

"Woah, woah, woah, hold on." Grunkle Stan said. "I'm not letting some random stranger stay in this house."

"What if I pay rent?" Danny asked.

"Soos, show the guy to his room." Stan flipped his story faster than a tourist's wallet.

"I got it!" Mabel said. "This way, Danny." They walked into the main house.

"So, you really want to stay here? You barely know us." Dipper asked suspiciously.

"I've got my reasons." Danny said vaguely. Then he hurriedly continued, "I mean, you seem like pretty cool people, and if you two do know all about the weird stuff in this town, then I want to stick with you."

Mabel squealed.


	4. Chapter 4

Dipper sat up suddenly in his bed. He rubbed sleep from his eyes as he looked around the attic room he shared with Mabel, searching for the source of the noise that had woken him up. He had thought he heard a strange, futuristic noise like a laser gun being fired.

Dipper tried to remember what he had been dreaming about. A faint echo of insane laughter came back to him and he shuddered. Bill Cipher.

"Mabel!" He hissed. This could be important. "Mabel! Wake up!"

"Uhhh…" she groaned. "Dipper, if this is about Waddles again-"

"No! I think…" Dipper hesitated, but he had learned never to trust strange noises or dreams. He hurried to her bed and whispered quickly. "I think Bill is somewhere close."

Mabel yawned. "Come on, bro. Stop being so paranoid."

"But Mabel-!"

"Tomorrow, Dipper. G'night." She rolled over. Dipper sighed and went back to his bed. Maybe it was nothing. Probably just an after effect of Bill inhabiting his body. He went back to a fitful sleep.

Danny exhaled slowly, and wiped his forehead. That was a bit too close. When he had been awoken by his ghost sense and come up to the attic to check it out, he hadn't expected to be led straight to Dipper. He was sure the boy was no ghost, but clearly something was interested in him. It didn't feel like a normal ghost, either.

When Danny had changed into ghost form to investigate and Dipper woke up, he barely had time to turn invisible before Dipper saw him. Danny had flown up to the ceiling to watch what happened. While the kid talked to his sister, Danny had distinctly felt another presence in the room. And he knew the presence felt him.

Dipper said something about a Bill. Did he know what was going on? This went deeper than Danny had anticipated. It was going to be harder than landing a few punches and sucking the fiend into his thermos. Something here was... different.

The next morning Danny woke up much later than everyone else. He entered the kitchen as Dipper and Mabel were cleaning up breakfast.

"Morning." he yawned.

"Oh, hey Danny." Dipper said. "What took you so long?"

"Didn't sleep so well last night."

"Want some Stancakes and Mabel juice?" Mabel asked, holding up a plate of pancakes. "It'll wake you right up!"

"Um, I think I'll stick with my granola bars." Danny said, eyeing the suspicious pancakes.

"Good choice." Dipper muttered.

Danny looked at him. "Hey, I've been meaning to ask. That chubby guy said you guys have some experience in the weird stuff around here."

"Uh, yeah. I mean, what do you know about it?" Dipper asked, slightly suspicious.

Danny thought for a moment. How much should he tell? It was clear this kid wasn't going trust or help him if there wasn't a good reason. "Well actually, I came here to do a bit of investigating. I was hoping you could help me."

Dipper's face lit up. "Wait, you're investigating the paranormal stuff in this town? We should work together!"

"You're checking it out too?" Danny asked, playing hesitant. This was perfect, if Dipper was already in this than Danny would waste much less time.

"Yeah! I've got this journal that's got stuff documented in it and everything!"

"Cool!" Danny was in luck. This was just what he needed.


	5. Chapter 5

"And over there's where the gnomes live, you want to stay away from those guys." Dipper continued.

"There are gnomes?" Danny asked. "What's so bad about them?"

"Trust me, you don't want to get in their way." Dipper said. He continued down the forest path. Danny was looking around interestedly.

"What's up with that tree?" Danny asked, pointing to a tall pine that was slightly given away by the rivets sticking out of it.

"Oh, that's a secret bunker!" Mabel said enthusiastically. "But we're not going down there again, that shapeshifter was creepy."

"A _shapeshifter_?" Danny sounded excited.

"Yeah, no way are we letting him out again. I'm worried as it is that he might escape from his cryogenic chamber." Dipper flipped the pages of his journal and kept walking past the tree.

"Wow, you kids are good with this stuff. And I thought I knew things!" Danny sounded amazed. "What's that over there?"

"That river?" Dipper asked, flipping through his treasured book to try and find some mention of the river, which he did. "I don't really know. The journal says to stay away from it at all costs. I think it's cursed or something." He brushed off this information casually. It hadn't affected them yet, so he wasn't much interested. One supernatural disaster at a time, thank you very much. Maybe later he'd check that out.

They continued to walk through the woods, Dipper pointing out places of past adventure. Danny half wished he had been here all summer. This sounded much more interesting than chasing Plasmius down every other day!

They were approaching a clearing in the forest near the Tent of Telepathy. There was an unusually perfect circle in the dirt and small burn marks around the edges.

"Hmm, what happened here?" Dipper asked.

Danny noticed a small wisp of breath escape his mouth. This was about to escalate quickly.

"I think this is where Gideon summoned Bill." Mabel said.

"Bill? Who's Bill?" Danny asked.

"Ugh, he's a really annoying mind demon who-"

"Now that just hurts my feelings, Pine Tree." A huge ripple in space washed over them all as the whole world went black and white. A yellow triangle with one eye and a bow tie had materialized above them.

"What are you?" Danny asked in astonishment.

"You don't recognize me, Deadman?"

"What?" Danny asked, more confused than ever.

"You know this guy?" Dipper asked.

"Yeah, I know who this kid is! We're practically cousins!" Bill laughed insanely.

"Wait, what?" Dipper and Danny said in unison.

"What do you mean we're cousins?" Danny asked angrily.

Bill laughed again. "I'm a demon, kid. Put it together." Danny's eyes went wide.

"What does that have to do with it?" Dipper asked, bewildered.

Bill fixed his single, hypnotic eye on Dipper. "Yeesh, Pine Tree. You call yourself intelligent?" He chuckled. "Anyway, I was just dropping in to see how Deadman Living here was doing. First day on the job, eh kid?"

"Why are you calling me that?" Danny asked, but his voice was more cautionary than confused.

"Haha! Surprisingly accurate description, huh?" Bill blinked his eye, which might have been his attempt at a wink.

"What are you talking about?" Mabel was looking at each of them alternately. She shared a confused look with Dipper.

Bill ignored her. "You ever faced a real demon before, Deadman?" He looked back at Danny, who was glaring back at him.

"Hm. Didn't think so. I'm looking forward to that." Bill examined his nonexistent fingernails. "Maybe I'll just leave you three to it, then. This should be fun!"

"Wait! How much do you- Wha- How did you-?" Danny was stuttering.

Bill laughed again. "Word gets around in this cute little world you've got. Well, have fun kid! You've got a lot to explore here in Gravity Falls... But hey, don't get in my way. I'll be watching you!" Bill disappeared in a flash of swirling light.

All three of them sat up in the middle of the forest clearing. Color had returned to the world, the forest came back to life, and Danny was breathing heavily.

"What was that all about?" Mabel asked, frowning.

"Not sure…" Danny said, almost to himself. "But I'm going to find out."

"Why was Bill calling you Deadman?" Dipper said curiously.

"Um, no idea. What did he call you?" Danny said quickly.

"Pine Tree. He likes being enigmatic." Dipper stood up and dusted himself off. "Let's get back to the shack."

"Yeah. I don't want to run into anything else that doesn't like me." Mabel started marching back the way they had come.


	6. Chapter 6

Danny checked the clock. 11:32. Stan was snoring in his living room armchair, and the twins were surely asleep by now. No one would miss him.

He concentrated, and in the blink of an eye his hair was white, his eyes were green, and he was wearing the black jumpsuit of his ghost form. He floated off the ground and stretched. Then he zoomed out of the shack like the walls weren't even there.

Danny flew through the woods, looking for the place where they had met Bill. It all looked a bit different in the dark. He soared over the strange river and headed towards a slightly lighter section of forest.

He landed in a small clearing, though not the one they had stopped at earlier. He took a few steps forward, looking around.

"Hey, hey, hey! What do you want?" A face poked down from the tree branch above him.

He jumped back. "Uh, sorry. I…" but he trailed off, taking in the creature before him.

"What?" the small man dropped to the ground and glared up at Danny from a height of not twelve inches. He had a short brown beard and was wearing a red pointed hat. "What's your problem, kid? Never seen a gnome before?"

"I, well, uh…" Danny stared at the tiny creature.

"What are you doing out here at this hour? And what exactly are _you_ , may I ask?" The gnome crossed his arms. "I was about to take my nightly squirrel bath."

Danny decided not to ask. "I'm…" he thought for a moment. He didn't want word getting to Dipper and Mabel about his ghostly investigations. He decided to go by his alternate name. "The name's Phantom."

"Oh, so you're some sort of ghost?"

"Uh, yeah." Danny tried to say it without hesitation.

"Okay then. Let's start over. Hi! I'm Jeff, leader of the gnomes." Jeff waved up at Danny. "And let me make this perfectly clear. Don't go bothering us a night again, or I'll have to imprison you, phantom or not."

"And how would you do that?" Danny said, laughing. "You're barely a foot tall."

"Listen to me, ghost kid. You don't want to-" But Danny had picked Jeff up and hung him by the back of his shirt on the nearest tree branch. No more time for chit chat.

"That's it!" Jeff shouted. "Gnomes of the forest, attack!"

An eruption of tiny men converged on Danny. He collapsed to the ground under their sheer numbers and within seconds was tied down like Gulliver. "Hey, what are you-? Get off me!"

"SHMEBULOCK!" A gnome with a haphazard gray beard was gnawing on Danny's leg.

"Stand down!" Jeff said. He had gotten off the branch and approached Danny's head.

"Shmebulock…" The crazy little man got off Danny and wandered into the trees.

"Like I said, don't mess with us. The gnomes are a powerful race! We-"

Danny rolled his eyes and went intangible, sinking into the ground.

"Hey! I'm not done with you yet!" Jeff called as Danny flew away, invisible.

He kept flying. Apparently there was more weird stuff going on here than he had anticipated. He would have to be more careful.

He continued to look for the place where they had met the demon. He flew into a cave full of loud noises, terrible smells and hairy man-beasts and was blown straight out again. He narrowly avoided being snapped up by a lake monster, and was forced to do some fancy flying to get away from something that looked like a cross between a gremlin and a goblin.

He touched down behind a large pine tree, hands on his knees, hoping that he had shaken the thing off. How was he supposed to know that it would become stronger if he shot ice at it?

Danny was breathing heavily as he peeked around the tree. The thing was gone. He sighed and slid down the trunk, sitting on the ground. This whole place was wrong, and a ton more complicated than he had bargained for.

"Bit different from your cozy little Amity Park, isn't it Deadman?" The high-pitched nasal tone of voice rang out just above Danny.

He shot to his feet, fists raised defensively. "There you are, demon! I've got some questions for you!"

Bill laughed. "Listen, Phantom. I gave you a break in front of those kids, but you've gotta do better than that if you want information."

"How did you know?" Danny asked. "About my ghost half, I mean."

"Oh, I know lots of things, Deadman. I've been through your little Ghost Zone and back. I recognized you at once. Thought you might turn up here sooner or later." Bill smirked. Or at least Danny thought so, it was kind of hard to tell.

"Look, I don't know what exactly you are, but I'm just going to get this over with, okay?" Danny shot into the air and fired a ray of green energy from his hand. Bill moved to the side, watching Danny amusedly.

"You wanna play, kid?" Bill pointed his finger at Danny, who barely missed the laser beam.

 _Okay, this might be difficult._

Danny shot more energy blasts at Bill, who avoided them almost lazily. When Bill shot back, his laser went right through Danny's shield and grazed his arm.

"Ah!" Danny grabbed his arm in surprise.

"That was a warning shot, kid. Don't go biting off more than you can chew."

"You know what?" Danny said as he fired another blast, which Bill didn't bother to dodge. The ray was absorbed into him with no effect, and Danny fumbled while taking out his thermos. "How did you-?"

Bill laughed. "I told you kid, you're not in Amity Park anymore."

Danny uncapped his thermos and pushed the on button. Blue light shot out of the end at Bill, but nothing happened. The demon mimed yawning as the light washed over him.

"What? That was supposed to- you should've been-" Danny stuttered. This was completely new to him. No ghost of any kind was able to stay out of the thermos.

"Kid, if you're gonna keep this up, I'll have to make things difficult." Bill rolled his eye.

"What do you want?"

"Me? Oh, nothing much. I think I'm just gonna sit back and watch all this play out. When those kids find out-!"

"They aren't going to." Danny said, teeth clenched. "And why are you even talking to me if you don't want anything from me?"

"You came looking for me, Deadman. And trust me, you'll want to talk again sooner or later. You have no idea what you're up against. I'll be here if you need me! Remember, YOUR CONSCIOUSNESS IS CRUEL HOAX BY THE LIZARD OVERLORDS BURY ALL YOUR GOLD WATCH OUT FOR THE GLOW CLOUD BYEEEEE!"

Before Danny could demand anything else from him, Bill had vanished in a flash of light.

Danny heard a gasp behind him.


	7. Chapter 7

Dipper woke with a start. He had heard it again- that strange sound like a laser gun being fired.

"Mabel! Mabel, wake up!"

"Dipper, seriously? Again?"

"No, really. I swear-" And then they both saw it. A streak of light heading from the Shack into the woods.

"Woah!" Mabel jumped out of bed and rushed to the window. Dipper was right behind her.

"What was that?" Dipper snatched his journal from the table at once.

"Let's go find out!" Mabel said, grabbing her grappling hook. ¨Mystery Twins!¨

They pulled on their shoes and ran out of the Shack.

"It went this way!" Mabel said, running ahead. "I see a glow!"

"Mabel!" Dipper huffed. "Are you sure?"

"Yeah, and if you don't hurry up we'll lose it!" She rushed ahead. They swerved through the trees as the light got dimmer and dimmer.

"Stop!" Dipper called. "That's gnome territory!"

"But Dipper-!"

"Mabel, we are not walking in on the gnomes in the middle of the night!"

"But the light is fading!" Mabel pointed at the dim glow that was indeed almost gone.

They continued to bicker for a few minutes before Dipper sighed and said "We'll just have to- look!" The streak of light was flying away from the gnomes in a diagonal. "There it goes!"

"After it!" Mabel shouted.

They continued to weave through the forest in pursuit of the light. It stopped moving suddenly. Mabel flung her arm into Dipper's chest as she slid to a stop. "Shhh!"

"Ow! Mabel!"

"Shh, Dipper, don't scare it!"

"Scare it? We don't even know what it is."

"Then let's find out!" Mabel started creeping toward where the light had stopped. Dipper hurried along behind her, looking through his journal for clues to the mysterious glow. Then both of them looked up at the same time as they heard an all-too-familiar laugh.

"It's Bill!" Dipper said, pulling Mabel to the ground.

"Bill doesn't glow like that," Mabel said, staying low. Then another familiar voice sounded out.

"Who is that?" Dipper said, "I think I've heard him before."

"Kinda sounds like Danny." Mabel said.

"I don't think Danny would be dumb enough to go out here at night after what happened earlier." Dipper said. "Besides, that voice doesn't quite match him. It's not exactly… human."

Mabel too heard the echo in the unknown voice. It sounded like Bill and the mystery guy were arguing, but they couldn't hear enough to distinguish words. "I'm getting closer," Mabel said.

"Mabel, no! Don't let them see you!" Dipper whispered furiously, crawling after her.

"Don't worry, Dipper. I'll be careful."

"Mabel!" Dipper groaned and continued to pick his way through the underbrush toward the conversation.

Suddenly Bill started yelling one of his weird tangles of words that he always did as he vanished. Dipper was far behind Mabel at this point, because she had not been taking much care to keep herself undetected. He saw her stop at the edge of the same clearing where they had met Bill earlier.

Mabel gasped. A boy was floating in front of her. He had pure white hair, and as he turned in midair to face her she saw that his eyes were glowing green. His face was familiar.

"Ma-!" He almost shouted something, but he cut himself off. "Uh, hello, um, child. What are you doing out here?" He looked terrified at the sight of her.

"Following you." She recognized him as the glowing entity they had been chasing around the forest. Though his suit was mostly black, he glowed with a distinct white aura.

Mabel looked over her shoulder. Dipper had gotten stuck in a bramble of thorns. They had a minute before he caught up.

"Following-?!" The boy shook himself. "Uhm, do you know what I am, then?"

"Nope!" Mabel said happily. "We just saw your light in the forest. What are you, then?"

"Uh, well…"

A thought occurred to Mabel. She gasped again. "Are you a superhero?"

"Well, not exactly, I-" The glowing boy broke off. He glanced over her shoulder.

"Oh, my brother is back there. I think he's stuck." Mabel said. "So tell me! You look so familiar… Wait, if you're not a superhero, how are you flying? You look human."

The boy sighed. "I'm a ghost. I-"

"You're dead?!" Mabel shrieked.

"What? Not exactly, I-"

Mabel gasped again, so loudly this time that she cut him off. "Danny!"

"What?!"

"Danny, you died? How? Was it Bill? Oh my gosh, how are we gonna explain this to Stan?" Mabel looked shocked.

"Wait a minute-" Danny tried to break in.

"Where's your body? Oh no, what about your family? What are we-" Mabel was near tears now.

"MABEL!" Danny shouted, startling her into silence. "I'm not dead!"

"But you just said-"

"Mabel, please, don't freak out." He held out his hands in an imploring gesture. He set down lightly on the ground next to her. "How did you know?"

"Know what?"

"That it was me?"

Mabel looked at him. "Well, it's kinda obvious. All that happened is your hair color changed. What, you think that's enough to make you unrecognizable?

"I had that impression. People back home haven't figured this out with years to try, and you get it in two minutes." Danny ran a hand through his hair.

"Years? I thought you just died. I saw you alive earlier today."

"Mabel, I'm not dead!" Danny said indignantly.

"Then how come you're a ghost?"

"I, well, had a sort of accident a few years ago. It gave me ghost powers." And he held out his arms as a ring of light circled his waist. The ring split in two and traveled up and down his body, transforming him as it went. Mabel stared as in only a second he looked like Danny Fenton again.

"OH MY GOSH! Ohmygoshohmygoshohmygoshohmy-" Danny clapped his hand to her mouth, silencing her.

"Look, you've gotta keep this a secret, okay? No one can know. To my enemies I'm Phantom, and I can't afford to give away my secret identity. Not even my parents know about this." Mabel nodded, and Danny took his hand away.

"Do it again!" Mabel said, looking up at Danny with wide eyes.

"Mabel, please-"

"I won't tell, I promise! But can I please see it again?"

Danny looked at her skeptically. She looked back at him with big pleading eyes.

Danny rolled his eyes, but he smiled and transformed again into Phantom.

"That's so cool!" Mabel squealed.

That's when they heard someone crashing through the brush behind them. Both jumped; they had forgotten about Dipper.

"Mabel, I told you to wai-" Dipper emerged from the bushes behind Mabel and caught sight of Danny. He let out a yell.

"What is that?!" he stared at Danny, or rather, Phantom.

"Excuse me-" Danny started.

Mabel laughed. "Dipper it's-" but Danny silenced her with a look. "It's, uh, a ghost! Ahh!"

"A ghost?!" Dipper gasped. "Where did it come from?"

" _It_ has a name, you know." Danny said, rolling his eyes.

Dipper stared. "A sentient being comprised of ectoplasmic-"

"Dipper, we've met ghosts before." Mabel said. "Remember in the convenience store-?"

"Yeah, I remember," Dipper said, cutting her off and turning a bit pink. "But those were different. This ghost is obviously more concentrated and powerful. Not merely a wayward spirit-"

"What are you talking about?" Mabel said.

"Mabel, I've done research in the journal. Ma and Pa were a low-category pair. This ghost could be significantly more dangerous!"

"Then why hasn't he attacked us yet?" Mabel said with a giggle.

"You know you could just talk to me." Phantom said. Dipper jumped but continued to ignore him. Instead, he pulled out his journal and started flipping through the pages, trying to locate the one that talked about higher-category ghosts.

"Okay… Why don't we start with a hello? Hi, I'm Phantom, your friendly ghost-fighting superhero. And you are?" the ghost held out his hand.

"Uh, Dipper." He shook it, surprised at how solid it felt.

"Hi Dipper. Now before you go all paranoid on me, let me explain something. I am here to help. I came to investigate some strange activity around this town, and I know what I'm doing. So please try not to get in my way."

Dipper stared at the Phantom. "But where did you come from?"

"Doesn't matter. I'm here and I'm on the case. I've been scouting the area. So don't worry, I won't bother you and soon I'll be out of here."

Dipper looked as if he wanted to argue, but Phantom shook his head.

"Come on, bro." Mabel said. "He's not dangerous. We were talking before you caught up."

"Fine," Dipper said, though still looking suspicious. "Then we have to get back to the Shack. Stan will kill us if he finds out we were out all night."

Mabel sighed. "Okay then, come on." She took Dipper's hand and started dragging him out of the clearing.

Dipper looked back over his shoulder just in time to see Phantom give a little wave and vanish into thin air.


	8. Chapter 8

Back in their attic bedroom, Dipper and Mabel were arguing.

"There's something going on with that ghost!" Dipper said.

"Dip, I told you, he's harmless. We had a nice little discussion while you were stuck in the bushes."

"I don't trust him. But what did you find out?" Dipper leaned forward eagerly.

Mabel shrugged. "Just that he's in the area and he's trying to protect us. He's some kind of superhero where he comes from."

"A _ghost_ superhero?"

"Yeah. Apparently. Well, from what I gather he's not a ghost all the time." Mabel said, falling onto her bed. "Can I go to sleep now? I'm ti-"

"Wait, how can he not be a ghost all the time? Death is a permanent state." Dipper was pacing the floor. It was quite irritating.

"I don't think he's dead. Just kinda magical." Mabel said, starting to snuggle under her blankets.

"How can you be so calm about this?!" Dipper continued to pace, talking to himself. "If he's not dead, then he must have some sort of power to change between forms- he couldn't possibly hold a ghostly state forever. That suggests that he's actually mortal, and gained powers through some event. But he could just be trying to throw us off the trail. We don't know exactly what he wants. On the other hand, he is not a normal ghost. He has color, a stable form, and density, which aren't usual characteristics of spirits. He must have some tie to the mortal world. But still-"

"Dipper!" Mabel said loudly, "Can we do this tomorrow? I don't care if he's the ghost of Bruce Wayne, I'm trying to sleep."

"Dipper! Get up, you need to clean the gift shop!" Dipper woke with a start to Stan's yell. Mabel was already up and downstairs.

As Dipper entered the kitchen, Mabel and Danny stopped talking abruptly.

"What took you so long?" Danny asked.

"I was up all night thinking about this thing we found last night." Dipper yawned.

"Oh…" Danny said slowly, "What did you find?"

Mabel looked at Danny with a half confused, half amused smile on her face.

"Oh, you're never going to believe it!" Dipper said, suddenly excited. Perhaps Danny could help him figure this out, if he had experience in these matters.

Danny raised one eyebrow. "Oh?"

"Yeah, we found some sort of ghost!" Dipper said. "I mean, we've met ghosts before, but this one was different."

"Wait, you've met ghosts before?" Danny asked.

"Yeah, Ma and Pa Duskerton." Mabel said. "That was a weird night." She shivered.

"Hmm…" Danny stared down at the table, apparently deep in thought.

"Oh, I forgot to ask you, Danny," Dipper said, "What exactly do you specialize in? I mean, you said you were looking for weird stuff, but like, what kind?"

Danny looked up. "Um, I actually do know a bit about ghosts. Back home, they're a bit of a problem."

"What? Where do you live?" Mabel asked.

"Amity Park. We get ghost attacks every few days, but it's normal for us. There's a few people who take care of that stuff."

"Like who?"

"Like my parents, for one." Danny rubbed the back of his head embarrassedly. "They consider themselves to be expert ghost hunters. They do have their moments. They've been trying to train me and my sister lately, so I do know a thing or two."

"Cool!" Dipper said.

"Your _parents_ are ghost hunters? How do you-?" Mabel cut herself off as Danny shot her a look.

"You can help us then!" Dipper said excitedly. "Let's go!"

"Wait what, now?" Danny started.

"Yeah! I bet we can find him. The forest isn't that big."

"Not that big?!" Danny was incredulous. "Are you crazy?"

"Let's do it!" Mabel said. Danny looked at her.

"What?"

"Let's do it!" She repeated. "I'm sure we can find him." She looked at Danny and raised an eyebrow. "Don't you think?"

Dipper nodded enthusiastically. He grabbed Mabel's hand and the journal out of his vest, running out the front door.

Danny followed them bemusedly into the forest.


	9. Chapter 9

"You know, a lot of ghosts only come out at night." Danny said, slightly annoyed. He was trailing behind Dipper, who was forging ahead with such enthusiasm that any nearby creatures must have been scared away long before.

Mabel giggled. She was walking slightly ahead of Danny. She fell back as Dipper continued on and whispered to him, "You should change. It would freak him out."

"But then he would wonder where I went." Danny stared determinedly at Dipper's back. It was tempting, seeing as the kid wasn't going to give up. He wanted to get some more research done, check out that Bill character. He was sure that was the main threat to this town, but he couldn't make any progress strolling aimlessly through the woods.

"I'll say you ran back to the shack for a minute." Mabel said, her eyes gleaming with excitement. "Please? It'll be hilarious!"

Danny smiled in spite of himself. Much the better way to get the confrontation over with. Dipper was so determined that he'd find Phantom eventually, no matter how much Danny put off transforming. "Okay, but forget the excuses. If we can keep this short, I have an idea." He looked through the trees ahead. Dipper was far in the distance. Danny ducked behind a tree and transformed into Phantom. Then he concentrated, and split himself into two.

"Woah!" Mabel squealed. Both Dannys shushed her quickly, one turning back to normal. "You can duplicate yourself?" Mabel whispered excitedly.

"Yeah, but I can't keep it up for long." Phantom said, looking at his double.

"Come on, we'd better hurry." Danny grabbed Mabel's hand and pulled her onto the path so they could catch up with Dipper.

"What's taking you guys so long?" Dipper called back to them.

"Mabel was dawdling," Danny said. He and Mabel both ran to catch up with Dipper.

"Hurry up then, because I'm sure we're getting close." Dipper continued to forge ahead.

"Do you even know how to locate a ghost?" Danny asked.

"Oh, duh!" Dipper rummaged in his backpack, pulling out a device with a small monitor attached to a long, thick wire. "There we go!"

"What exactly is that?" Danny asked, looking worried.

"It detects supernatural activity. It's just a prototype, though. This will be its first test." Dipper said excitedly.

"Where did you get it?"

"I made it, following some instructions in the journal. If I did it right, it should alert us to any nearby ghosts." Dipper turned on the machine. It immediately started beeping. "We're close!" He examined the monitor closely, slowly turning on the spot. The device beeped faster and faster, until it was one unending tone. Dipper looked up. The wire was pointing to Danny.

"Wha-?" But before Dipper could form the word, Phantom appeared between them. Dipper gasped.

Phantom landed on the forest floor and put his hands up ironically. "Okay, fine, you found me. What do you want?"

"I want to know what you are," Dipper said excitedly. "I have so many questions! What are you really here for? What kind of ghost are you? What are your abilities? How-"

"Slow down, kid!" Phantom said. "Listen up, I'll tell you one more time. I'm here to help. I'm a Phantom, a powerful ghost. I specialize in fighting malevolent spirits. From what I understand, there's some sort of demon causing trouble around here. I'm going to take care of him and then I'll be on my way. Got it?"

" _You_ take care of Bill? All by yourself? How powerful are you?" Dipper looked skeptical.

"Trust me, I can handle myself. Anymore questions, kid? I'm in a bit of a hurry."

"Please just tell me what exactly your powers are."

Phantom rolled his eyes. He began listing on his fingers: "I can fly, become invisible and intangible, possess people, shoot energy and ice blasts, detect ghosts, heal superquickly, create destructive sonic waves with my voice…" He thought for a moment. "Yup, that's it."

Dipper stared at him, mouth open. "That's amazing! How have I not heard of you before?"

Phantom looked half amused, half exasperated. "My powers aren't that uncommon. I deal with similar ghosts on a daily basis."

"Where?" Dipper looked amazed.

"Oh, all around." Phantom glanced behind him, where Danny was staring ahead, looking vacant. "Listen, I've got to get going."

"Wait, one more thing! I have a theory. You can't be a normal ghost. I've seen other ghosts. You have a much more stable physical form, and color, and density. According to my journal, those aren't normal characteristics of ghosts. In such a concentrated form, you couldn't last long. You must have another form, something that takes less energy than such a powerful ghost."

Phantom looked startled, and maybe a bit scared. He glanced fleetingly at Mabel, then replied, "You're sharp, Dipper. But unfortunately that's forbidden information." He glanced behind him at Danny again, then said, "Okay, I gotta go. See ya around, kid. Or, you know, not." And Phantom disappeared.

Danny gave a little start. "So, Dipper?"

Dipper was still gazing at the place where Phantom had disappeared. "That was so cool! But he still didn't really answer my questions."

"I thought it was pretty clear." Danny said, walking over to him.

"But he barely talked to me! I wanted to keep asking-"

"Come on, let's go back to the Shack. You got what you came for." Danny started walking back along the path they had taken.

Mabel looked at Dipper and shrugged. "You did find him. I think Danny just wants to go back."

"Ugh, now _he's_ being evasive." Dipper grumbled as he followed Mabel back to the Shack.


	10. Chapter 10

Danny tiptoed past the bottom of the attic steps. It was past midnight, and he was determined to get the scoop on that Bill demon. He had almost given himself away with Dipper earlier, and he couldn't afford to stick around much longer. He was confident that Mabel would keep his secret, especially if she never saw him again. But Dipper was way too curious, and would probably follow him back to Amity Park if he found out he was Phantom.

Danny stopped dead as he heard a creak from upstairs. He had to make sure the kids stayed out of this. He was here to do a job, and he had to get it done quickly and go home. Secrecy was imperative.

Confident now that no one else was awake, he hurried out of the Shack and into the woods. Just to be safe, he would wait to transform until in the cover of the trees.

Dipper froze, hidden in the complete darkness. Danny was looking toward the stairs. Dipper was sure that he had heard the stair creak as Dipper had set foot on it. Danny shook his head and continued to creep towards the door. Dipper slowly followed, taking care not to make any more noise. He got to the bottom of the stairs as Danny slipped out the door. He hurried after and peeked through the door. Danny was running into the forest. Dipper hurried to catch up, but lost sight of him as he entered the trees.

Dipper crept from tree to tree until he heard Danny's voice.

"Finally…"

Dipper turned toward the voice and saw Danny standing in a clearing. Dipper quickly ducked behind a bush to watch.

Danny looked around one more time, then sighed. "I'm goin' ghost!" he said to himself, a determined look on his face. Then a ring of white light appeared around his middle. It split and passed up and down his body, and as it went, he was transformed.

Dipper gasped. Danny had turned into… "Phantom?!"

Danny/Phantom turned, startled. "Huh? What-?"

"You were Phantom the whole time?" Dipper said incredulously, emerging from his hiding spot.

"I-"

"I can't believe this! You lied to me? All of that interrogation stuff- you were just trying to distract me!"

"Dipper-"

"Did you even consider that I could help you? I trusted you! I showed you the journal!" Dipper was shouting.

"Look, I couldn't have anyone else finding out, the whole point of a secret identity is to keep it _secret_!" Now Danny was on the attack.

"What do you mean anyone else? Do other people know?" Dipper stared accusingly at Danny, trying to catch him lying again.

Danny shifted nervously. "Well, Mabel guessed." He said, looking slightly ashamed.

"Mabel?! She kept this from me? Seriously?"

"Well, I asked her not to tell. Like I said, the point is to keep it secret."

"But we tell each other everything! You wanted my own sister to turn against me!"

Dipper was yelling so loudly that he was sure to wake something up. Danny glanced around the forest clearing quickly before saying, "Okay, that's going too far. Do you really think I'd do that?" Before Dipper could get out another word, Danny continued. "I came here to do something. I thought if you guys could give me the background info I could get it done faster. The first time you found me, Mabel figured out who I was within a minute. I swear I didn't tell her. You didn't know, and I saw no reason to enlighten you. The more people who know who I am, the more dangerous it is for me. I wanted to get this done and get out. Now will you please leave me alone to get my work done?!" Danny seemed unusually angry.

"You can't just leave me out of this!" Dipper shouted back.

"Yeah? Watch me." And Danny vanished.

"Come back here!" Dipper yelled, spinning on the spot to try to spot him. "I can't believe you're doing this to me! I thought we were _friends_!" But try as he might, Dipper couldn't get Danny to reappear. He was probably deep in the woods by now.

Dipper stormed off back to the Shack. It was time he had a word with his sister.

Danny zoomed off into the trees, invisible. Dipper was really starting to get on his nerves. He should have known the kid would figure him out eventually. He groaned to himself. What was he going to do in the morning? Everyone else would question it if he wasn't back at the Shack the next day.

He would just have to make some excuse and get out as fast as he could. His mission was in jeopardy.

Mabel woke with a start. Dipper was shaking her, an uncharacteristic look of anger on his face.

She yawned. "What is it, bro?"

"Why didn't you tell me about Danny?"

Mabel was suddenly wide awake. "What about Danny?" She asked nervously.

"Phantom, Mabel. I know." Dipper crossed his arms and looked at her accusingly. "Come on, you never keep secrets from me. What gives?"

She looked down. "I'm sorry Dip. Danny asked me not to say anything."

"So what? You're my sister! And you know I'd want to know about something like this." Under normal, non-betrayal circumstances, Dipper would be ecstatic to find a human-ghost hybrid. He could add so much to the journal. But both Danny and Mabel had deliberately kept this from him. How could they? Especially Mabel, she knew him too well.

"Dipper, I'm sorry. I just…" She trailed off, not knowing what to say. Dipper shook his head and climbed into the bed across from hers. He eventually fell asleep with his back to her. Mabel didn't fall back asleep at all.


	11. Chapter 11

According to Stan, Danny had showed up early in the morning to let him know that he was leaving, and to thank him for his hospitality. Mabel looked disappointed as he told them this over breakfast, while Dipper glowered. _Good riddance_ , he thought.

He glanced at Mabel, who gave him a sort of pleading, apologetic look. He looked back at his bowl of cereal.

Danny was wandering through the woods in human form. He kicked a rock to let off his frustration. It didn't make him feel any better. Did Dipper really expect him to tell his deepest, darkest secret within a week of meeting him? How could he have been so careless as to let Dipper see him transform? That kid was too nosy for his own good.

And how was he going to get anything done now? He didn't know enough about this strange town to go it on his own. Maybe he should just leave.

But then, all the other innocents here would suffer. Danny was sure that Bill wasn't up to anything good, and the demon was much more powerful than most fiends he had fought before. He was right up with Pariah Dark on the danger scale. Maybe even higher. Danny didn't know exactly what he wanted yet.

No, he had to stay. He'd just avoid the Pines until this was all over. He pushed through more brush as he ventured deeper into the forest.

"Dipper, I'm sorry, I-"

"Leave me alone."

"But-"

"No, Mabel." Dipper sat on his bed, facing the wall. He looked down at his journal, flipping through the pages about ghosts. He had read them a thousand times, but he couldn't bring himself to do anything else.

He had barely spoken to anyone for the past two days. Danny hadn't come back. That's what he got for trusting a ghost. A slippery, supernatural being that was anything but human. Dipper couldn't believe that he had been taken in like that. He couldn't allow himself to be tricked again, not by anyone or anything.

He heard Mabel leave the room for dinner as he turned another page. He read about the generals of ghosts, the different categories, and ways of getting rid of them. But somehow, Phantom didn't seem to tally with the other accounts he could find. He definitely had a solid, physical form, and that should rule him out as a ghost completely. Maybe he was a poltergeist? Dipper kept looking as the sky outside darkened.

Nowhere in the journal did it mention a ghostly ability to disguise themselves as human. How could he have possibly held that form for so long? Unless Phantom was something entirely different, something more powerful. He had said that he was here to fight other ghosts, but why would he do that? There was nothing specifically posing a threat. Well, except maybe Bill.

Bill! Dipper slapped his hand to his forehead. Bill had given him the answer at the very beginning! He had called Danny "Deadman". We're practically cousins, he had said. Was Phantom here to work with Bill, or against him?

Dipper lay back heavily on his bed. He couldn't decide what to think or how to feel. Danny had seemed trustworthy, but Phantom…

Suddenly, Dipper heard a scream coming from outside.

"Mabel!" Dipper jumped off his bed and ran down the stairs. He swung around the post at the bottom and crashed through the door, tripping down the porch steps and heading toward the forest. Mabel screamed again. It was a terrifying sound, desperate and scared. He had never heard her scream like that.

"Grunkle Stan!" He called, trying to get someone else to notice. "Soos! Wendy!" But nobody seemed to be around. He kept sprinting towards the woods.

She sounded like she was just inside the forest. Close, but he couldn't run fast enough. His feet felt huge and clumsy as he stumbled over rocks and exposed roots. He saw a white glow up ahead in the direction of Mabel's screams. Phantom! Was he attacking her? Dipper ran even faster.


	12. Chapter 12

Danny was wandering aimlessly through the woods when he heard the scream. He whipped around, looking for the source. It had sounded like Mabel. She screamed again, and Danny took off running. He transformed mid-step and flew through the trees at top speed.

He saw Mabel up ahead in a clearing, backing away from something. As he neared, he saw that it was Skulker. What was Skulker doing here? As Danny zipped in behind Mabel, Skulker shot a glowing green net at her. It wrapped around her and forced her to the ground. She tried to scream again, but a lump of ectoplasm acted as a gag.

"Oh, hello, Ghost Child." Skulker said, looking at Danny. "Come to help me?"

"Let her go, Skulker." Danny said warningly.

"But surely you understand why we need her," Skulker raised an eyebrow. "She is one of the ten I have been tasked with retrieving."

"Who told you to capture her?" Danny asked, arms crossed.

"The entire Ghost Council, whelp. Didn't you know?" Skulker looked astonished.

"Know about what?" Now Danny was confused. He looked back at Mabel, whose eyes were wide through the net.

Skulker laughed. "You spend too much time in the mortal world, naïve child." He became serious. "There is a grave danger coming to this world. All of the ghosts have fled to the Ghost Zone. Surely you noticed."

Danny landed softly on the ground between Skulker and Mabel, still in a defensive stance, but listening. "I have noticed that, yeah. Not even Plasmius is around anymore."

"That is because even that hybrid fool can recognize that something is about to happen," Skulker said.

"But wait," Danny shook his head, "If something is going to happen to this dimension, that means that the Ghost Zone will be affected too. They mirror each other, remember?"

"Exactly. There was a meeting of the Ghost Council, and it was decided that for the safety of our own dimension, we must prevent this catastrophe from happening."

"Then why do you need the girl?" Danny asked, taking up his defense again.

"I need more than just the girl. I require ten specific humans that can prevent the catastrophe."

At that moment, Dipper burst through the bushes behind Danny. He cried out as he saw Mabel tied up, but in a flash Skulker had a net and gag on him, too.

"There's another one. This might be easier than I thought." Skulker made to pick up the twins and put them in his containment device, but Danny blocked his path.

"Leave them alone," He said through clenched teeth. His hands started to blaze with green light.

"Have it your way, whelp." Skulker activated his weapons system. He shot a few glowing blades in Danny's direction, forcing him to fly to the side to avoid them. "I will take your head on my wall any day."

Danny evaded another shot and turned the fight away from the twins. He couldn't let them get hurt. He fired a few ectoplasmic rays from his hands, taking out one or two of Skulker's weapons. As a barrage of darts soared toward him, he put up a shield while he fumbled with the Fenton thermos. A dart nicked his arm and he gasped in pain. But the cut didn't seem to be deep.

"Is that the best you can do, metalhead?" Danny said. On the edge of his vision he saw Dipper roll his eyes. _Shut up_ , he thought.

Skulker laughed, which gave Danny enough cover to open the thermos and activate it. Skulker tried to dodge it, but the streak of light emitting from the thermos hit right on target and sucked a tiny green blob of ectoplasm out of his head. The empty metal suit fell over, and Danny put the lid back on his thermos.

He turned and floated over to Dipper and Mabel, who were still tied up on the ground. He got them out of the nets and helped Mabel to her feet.

"Sorry you got stuck in the middle of that," he said apologetically.

"It's okay, she said, rubbing her wrist. "That was cool, the way you fought him off. What happened to him?"

"He's in here," Danny held up the thermos. Then he jerked his thumb over his shoulder. "That's just his exoskeleton. He's pretty tiny without it."

Dipper grabbed Mabel's hand and pulled her back, away from Danny. "Why did you save us?" He asked.

"Well, I couldn't let that psycho stick you in a cage, could I?" Danny half laughed, but he knew Dipper was remembering the betrayal.

Dipper looked at him with distrust. Danny could see that he would have to do some thorough explaining.

He sighed. "Look, I'm really sorry, Dipper. I shouldn't have kept it a secret." He averted his eyes, rubbing the back of his head. "I was just trying to keep a low profile, but I did ask for your help. I should have told you."

"Tell me what you're really doing here." Dipper said, stepping in front of Mabel as if to protect her.

"Dip, he just saved us," Mabel said quietly.

"I need to know the truth, Mabel." He said, looking back at her.

"I'm here because it's my job to protect people from ghosts, or any sort of weird disaster. Our readings indicated a high level of supernatural activity here, so I came to investigate. After I met Bill, I knew I had to take care of him. It's what I do."

"But what _are_ you?" Dipper asked. "Are you a ghost or a human?"

"Both. It's sort of hard to explain." Danny looked self-conscious. "A couple years ago my parents tried to create this portal to the Ghost Zone, but it didn't exactly work. When I went to check it out, it zapped me and turned me into… this." He landed on the forest floor and transformed back into Danny Fenton again. "I can change back whenever I want, but I have all the powers of a full ghost."

"Cool…." Mabel said.

"Yeah, but it is a burden at times." Danny said.

"So you're really not going to hurt us?" Dipper asked.

Danny looked indignant. "Of course not! I never use my powers against the innocent. Well, except sometimes on Dash. But he's a jerk." Danny laughed again.

Suddenly Dipper saw that Danny was an ordinary teenage boy. He had flaws and enemies, but he was also lighthearted and fun. He wasn't that different at all.

Dipper joined in Mabel and Danny's laughter.


	13. Chapter 13

"Hey Grunkle Stan, guess who's back?" Mabel said as they entered the Shack. But there was no answer. "Grunkle Stan?" Mabel said, peeking around the corner into the living room. Nothing. "Where is he?"

"He wasn't here earlier when I came to find you either," Dipper said, looking concerned.

"Does he usually go out at this time of night?" Danny asked.

"Not unless he's pulling a heist. He likes watching Baby Fights right about now." Dipper said, rolling his eyes.

Danny decided not to ask. "Then where is he?"

Mabel shrugged. They searched the Shack, but they found nothing except one of Wendy's magazines on the counter of the gift shop.

"That's so weird…" Mabel said pensively.

"Wait a second, that thing that almost captured us-!" Dipper exclaimed suddenly.

"Skulker? What about him?" Danny asked quickly.

"He said he was looking for ten different people. What if-?" He didn't need to finish his sentence. At that moment, all three of them saw Wendy's axe lying on the ground, as if it had been thrown and missed its target.

They rushed back to the forest clearing where Skulker's suit was still on the ground. Danny started examining it, trying to find the containment device. "If he got them, they'd be somewhere here. Or in the Ghost Zone." He didn't want to think about having to search Skulker's lair for the captives.

"The Ghost Zone?" Dipper asked. "What-?"

"It's where most ghosts live," Danny answered preemptively, still checking the suit for hidden compartments. "Weird dimension, it's like the Twilight Zone in there. Aha!" He pulled out a small cube, which he threw on the ground. It expanded into a cage the size of a car, and inside it were Wendy, Stan, Soos, and for some reason, Pacifica Northwest.

"Finally!" Pacifica said. "That thing has had me in here forever!"

"Pacifica? What are you doing in there?" Dipper asked.

She rolled her eyes and crossed her arms. "Don't ask me. That freaky blue man did it."

"And we've had to listen to her complain about it," Stan said grumpily. "Can we get out of here now?"

Wendy kicked the door open and all four of them stumbled out. "Yeesh, what is up with that guy?" Wendy asked, looking at the immobile suit.

"Long story," Danny said. All four of the captives jumped. They hadn't seen Danny until then. Luckily, at this point he was still Danny Fenton.

"I thought you'd skipped town, kid." Grunkle Stan said. Then he grinned and added mockingly, "Couldn't get enough of the mystery?"

"Who's this?" Wendy asked.

"Oh, that's Danny," Mabel said cheerfully, "we've been showing him around lately."

"Cool. Adventure buddy." Wendy punched Danny lightly on the arm. Danny laughed. Off to the side, Dipper glowered.

Pacifica folded her arms. "Great catchup, losers, but I'm going home." She marched out of the clearing.

"Need a ride?" Soos asked. "I've got a pickup truck!"

She looked over her shoulder and scoffed. "Puh-lease. I can get home without riding in your piece of junk." She made to take a step forward, but seemed unsure of which direction to go. "Uhh…" She looked around the forest, trying to see any sign of civilization. Slightly resigned, she mumbled, "Fine. Just get me out of here."

"Hey Soos, could I get a ride too? My dad's probably going nuts." Wendy said, catching up to them.

"Sure thing, dawg." Soos said. The three of them walked out of sight through the woods.

"We'd better get back too," Dipper said, stifling a yawn.

Mabel nodded, and she and Stan started walking back towards the Shack.

Dipper fell back, walking next to Danny. "Look man, I'm sorry." He said, looking down. "I just… I guess…" he trailed off, unsure of what to say.

"Hey, no worries." Danny said, waving his hand carelessly. "I get it. But we're on the same team, so now let's just work on stopping Bill, okay?" His voice got soft and oddly serious. "I don't think I can do this alone. I'm going to need your help."

Dipper nodded. "Okay, on one condition."

"What is it?" Danny asked, slightly apprehensive.

"You have GOT to show me those powers!" Dipper said, smiling hugely.


	14. Chapter 14

Dipper, Mabel, and Danny got up at the crack of dawn the next day. Dipper and Mabel wanted to see a demonstration of Danny's abilities, but Danny thought they should be looking for Bill.

"You can't really find Bill," Dipper said. "Not if he doesn't want to be found. He lives in the Mindscape, and only reveals himself on his terms. At least, as far as I can figure out." He shrugged.

So Danny resigned himself to a presentation of his powers. They retreated far enough into the woods that no one would hear them, and made sure that no one had followed them. Then Danny dazzled the twins with his powers. It was really very fun for all of them, and Dipper and Mabel were a very good audience. They gasped and screamed as he disappeared, flew through trees, and duplicated himself. Mabel almost died laughing when Danny overshadowed Dipper.

As Danny exited his body, Dipper shuddered. "Okay, that was weird. You can do that to anyone?"

"Yeah," Danny replied, "And they usually don't have much memory of it either, unless they already know what's going on. I used that one to get myself out of detention once." When Dipper and Mabel looked confused, he added, "I overshadowed my dad. Probably shouldn't have done that, but I was just figuring things out then." He smiled good-naturedly.

They laughed.

For most of the day the trio wandered through the forest, exploring. Danny's powers came in handy when dealing with the creatures they encountered, at least, with Dipper's direction.

"Confuse it!" Dipper shouted from where he was crouching behind a tree with Mabel. Danny was in ghost form, fighting a particularly aggressive Gremloblin. "But don't get it wet, and don't look into its eyes! We need a reflective surface!"

Danny nodded and darted around the monster, blasting it with his ghost ray. It swiped at him, but he went intangible and avoided its razor sharp claws. He duplicated himself and three Dannys zoomed around the creature, confusing it, while a fourth created a reflective shield in front of its face. It looked into the mirrored surface and screamed, running away into the forest.

Danny reformed as one person and changed back to human form. "That was insane!" He said, slightly out of breath. "I fought one of those my first night here, but you made it so much easier." He grinned at Dipper, who was emerging through the trees.

"That fight was awesome!" Dipper said. "I'm telling you man, we make the perfect team!" They high fived.

Mabel laughed self-consciously, feeling like she was intruding."That was amazing, Danny. Can I keep one of your clones for myself?" She laughed, just managing to keep the uncertainty out of her voice.

Dipper and Danny laughed too, but Danny didn't reply. The two boys continued to walk through the forest, talking excitedly about all the different anomalies they could check out with the help of Danny's powers. Mabel trailed behind them. She wasn't used to feeling so left out.

Mabel followed the boys around for an hour or two, but after a few more monster fights and failed conversation attempts, she went back to the Shack.

* * *

Dipper and Danny were laughing, stumbling slightly as they headed back to the Shack. They had stayed out all day, and it had been dark for at least an hour now. Dipper had taken a particular interest in Danny after the sun had gone down, observing the otherworldly glow that surrounded him. Dipper had filled out an entire chapter in his journal already with new info on Danny.

They opened the front door a bit louder than was strictly necessary at that time of night. Danny laughed again and shushed Dipper. They were both giddy from their fun-filled day. Dipper grinned and waved goodnight, heading upstairs. Danny stretched and yawned as he made his way down the hall to Soos's break room (the nice one, not the heater cupboard).

When Dipper entered the attic bedroom, he found that Mabel was still awake, sitting upright on her bed and facing away from him.

"Oh, hey Mabel," he said with a yawn. "I thought you'd be asleep by now."

Mabel shook her head silently. Dipper tilted his head in concern, worried by her odd behavior.

"Mabel?" He asked cautiously.

She didn't answer.

"Mabel, what's up?" he approached her and put a hand on her shoulder. She turned to him, and he saw a sheen of tears on her cheeks. Dipper was shocked. "Mabel, are you okay?"

Mabel pulled her sweater up over her head. Dipper climbed onto her bed and sat next to her. "Mabel, what's wrong?"

She mumbled into her sweater, "Like you care."

Dipper pulled back, shocked. It was very unlike Mabel to act like this. "Of course I care! What's up?"

Mabel pulled her sweater off of her face. "It's just… you and Danny are suddenly such good friends and now you're leaving me out. You didn't even care when I left today!"

Dipper rubbed the back of his head uncomfortably. He hadn't really noticed when Mabel had left, he'd been so absorbed in Danny. "Mabel, I'm sorry. I-"

She interrupted him. "You're my best friend, Dipper. You can't just leave me because you found some weird new thing to study!"

"Danny's not a _thing_ ," Dipper said irritably, "He's my friend. Don't forget that he saved our lives, Mabel. You can't be like that about him!"

"I wanted him to be my friend too!" Mabel's voice was rising. "But neither of you have paid any attention to me. What's the point of me even being here?"

Dipper was really angry now. "You know, maybe there isn't any. If you're so mad at us, why are you still hanging around?"

Mabel was crying again, but she didn't back down. "I'll leave you alone then. It's obvious you don't want me around."

"You're right, we don't! Not if you're going to act like this!" Dipper shouted.

"Fine!" Mabel turned away from him and pulled the blankets over her head.

"Fine!" Dipper said, stomping over to his own bed. He didn't go to sleep for a long time.

* * *

*Guess who finally updated? Sorry for the long wait you guys, I got some serious writer's block for this chapter. But don't worry, I'm over it and big things are coming!*


	15. Chapter 15

Four days later, Mabel was still sulking. She was up in the attic with Waddles, watching Danny and Dipper heading toward the woods on this beautiful summer morning. They were talking and laughing as they strolled away from the Shack. She'd never felt so isolated before. No matter what had happened in the past, Dipper had always been by her side. Now without him, she realized how much she relied on his company. Even if they disagreed sometimes, she needed him.

She lay on her bed, propping up Waddles next to her. "What am I going to do, Waddles?" she asked him sadly. "I just want them to include me…"

"That can be arranged," said a snide, nasal voice.

Mabel turned with a jump as the world became black and white, and a familiar triangular figure appeared in the air above her. Waddles squealed in fear and dashed under Mabel's bed.

"Hiya, Shooting Star," said Bill. "Looks like you could use some help."

"Not from you!" Mabel said angrily. "What do you want?"

Bill looked as offended as a one-eyed triangle could. "I just want to help, kid. Seriously, even I understand what it's like to feel left out." He actually looked somewhat sincere. "I can help you."

Mabel wasn't sure that any of Bill's methods would end up well, even if he really did want to help her. But she was tempted. She knew she'd regret asking, but she replied. "What do you mean?"

"I can guarantee you'll be included with Pine Tree and Deadman. No effort on your part, and I won't even mess with their minds. I'll just make sure they don't leave you out."

"Why would you help me, though?" Mabel asked suspiciously.

Bill shrugged. "You might have gone against me in the past, but no one should have to go through complete isolation. Least I can do, Shooting Star." He looked like he really understood how she was feeling. Being so alone was taking a toll on her.

She was willing to do almost anything in order to have some fun with Dipper again. And maybe even have a chance at Danny! But still... "You promise it won't hurt them?" She asked, just to be sure.

"Trust me, kid, I'm only gonna do one thing and then they'll pay attention to you." he held out a hand wreathed in blue fire. "Deal?"

Mabel took a deep breath. "Okay, then." She reached out and took the demon's hand.

Immediately she felt a ripping sensation deep inside her, and a fleeting but excruciating moment of pain. When she was aware again, she felt oddly suppressed and trapped. But nothing seemed to be different, except-

"Wow, you sure are gullible, Shooting Star." Bill's voice came out of her mouth. "After the puppet deal with Pine Tree, you should have been more careful."

Mabel tried to scream, but nothing happened. She tried to run, but her legs wouldn't work.

Bill's insane laughter erupted from her. "Nice try, kid, but you have no control here. I couldn't risk you warning the others like Pine Tree did, so I'm keeping you in here with me. But you're gonna be trapped inside your own body for a long time." He laughed wildly again, and Mabel's consciousness tried to cry.


	16. Chapter 16

Deep in the Ghost Zone, Skulker returned to the Ghost Council with a report.

"The Phantom boy is preventing me from collecting the ten members of the zodiac." Skulker said, "He does not understand the danger we are in!"

"Surely you can find a way around him," one Observant said.

"Have you managed to locate all ten members yet?" Another Observant asked.

Skulker looked annoyed. "I have located all but one. The six-fingered hand still eludes me. It is as if he isn't even their world-"

"Impossible," An Observant overrode his protests. "Those humans have no access to the Ghost Zone, and any other dimension would be extremely difficult to break through to. You have not searched hard enough."

Skulker ground his teeth in anger that anyone would question his hunting skills. "Fine, I'll keep looking, but the whelp will continue to try to thwart my capture of the zodiac. We need to incapacitate him."

"Don't worry," Clockwork spoke up for the first time. "He will be kept busy for the current time. The Cipher demon has entered their world, and the boy is the perfect person to stop him from growing in power. All will be as it should be."

The Observants looked at each other uneasily, as they had always disliked Clockwork's interpretation of the future. "Are you sure-?" One of them said, but Clockwork cut him off.

"Sometimes we must interfere and sometimes we should not. Let what will happen happen."

Clockwork's vague answer did not please the Observants. One continued as if this last comment hadn't been voiced.

"If the Phantom boy will be busy deterring the demon, then you must capture as many of the zodiac as you can, Skulker." The Observant glared at Skulker. "Before the demon gains too much power."

"I will," Skulker said, nodding curtly at the panel of Observants and then again at Clockwork. He wasn't sure how well his mission would go, but he trusted Clockwork, and he was not voicing any other objections.

"Then go," An Observant said, "And be as quick as you can."

Skulker nodded again and activated his suit, flying back to the portal that would take him to the human world.


	17. Chapter 17

Dipper and Danny were conducting more 'experiments'. If 'experiments' meant screwing around with Danny's powers.

Dipper was strolling down the main street in town, Danny floating invisibly at his side. "Okay, there he is," Dipper muttered out of the corner of his mouth, jerking his head towards a dark-haired teenager.

"The emo kid?" Danny whispered.

"Yeah, his name is Robbie and he's a jerk. I'll get him out of the way, and you scare the pants off him!" Dipper tried to keep a straight face as Robbie spotted him.

Danny chuckled softly, watching Robbie walk over to them, though he could only see Dipper.

"What are you doing out alone, kid?" Robbie said aggressively. "Where's your lame sister, did she find someone cooler to hang out with?"

"Hey, Robbie," Dipper said nonchalantly, "Where's Tambry? She dump you already?"

Robbie glared. "She's at a dentist appointment, for your information. And-"

"Hey, you want to see something cool?" Dipper interrupted. "I guarantee you're going to like it."

"Yeah, like I'd go anywhere with you, loser." Robbie turned away and walked in the opposite direction from Dipper, into an alley off the street. Suddenly, Robbie's feet froze to the ground in a layer of ice. "Hey, what the-?"

A green glow appeared around a few pieces of trash in the alley started floating in circles around Robbie.

"Ahh!" Robbie yelled, trying to take a step back and landing on his butt as the ice broke. The trash dropped to the ground and Phantom appeared, translucent, above Robbie. Robbie screamed and scrambled backwards, Phantom following him with a blank stare.

"WooooOOOoooo," Phantom said in the scariest voice he could muster. He reached out a single hand toward Robbie, who jumped up and ran from the alleyway screaming.

"GHOST! THERE'S A GHOST! GET RID OF IT DIPPER!" But he was out of sight before Dipper could have done anything,

Dipper was on the ground, laughing so hard he couldn't breathe. Phantom turned back into Danny and burst into laughter as well.

"Th-that… was… AWESOME!" Dipper said, panting.

Danny bent over, holding his stomach. "Did you see the look on his face? Priceless!"

Dipper wiped a tear from his eye, then said, "We should go tell Mabel! She'll love it!"

Danny nodded and they started heading back towards the Shack. They met Mabel just outside- she was chasing Waddles around the yard.

"Come here, come back you stupid pig!" She said, her voice a little more nasal than normal.

"Hey, Mabel, are you okay?" Dipper asked, worried.

"Oh," Mabel turned towards Dipper and Danny, "Hey P- I mean Dipper. You're back early."

"Mabel, are you okay? You sound like you have a cold," Danny said with concern.

She shrugged. "It's nothing."

"Okay…" But Danny had a bad feeling about this. As he and Dipper walked past Mabel to get a drink in the Shack, his ghost sense went off. He gasped, and Mabel turned her head to look at him. Something was wrong with her, something about her eyes….

As they entered the Shack, Danny pulled Dipper quickly into the kitchen.

"Hey! What's up?" Dipper asked, confused.

"Dipper, I think there's something wrong with your sister." Danny said quietly, looking over his shoulder as though he expected someone to be watching them.

Dipper tilted his head to the side. "Why, because she has a cold? What's wrong with that?"

"No! Dipper, I know the signs of someone who's been possessed by a ghost. My ghost sense went off when we walked past her, and she's not acting right. I think she might be-"

Dipper waved him off. "What ghost would want to possess Mabel? I think she's just out of it because she's sick. Or maybe she's mad because we've been leaving her out…" he trailed off guiltily.

Danny looked skeptical, but he said, "Maybe. I'm going to keep an eye on her, though. Just in case."

Dipper shrugged. "I guess we should include her more anyway. Let's go tell her about Robbie!"

Danny was still worried about Dipper's lack of concern, but he followed him out to where Mabel was standing in the yard.

* * *

"I've really missed you, Dipper. I think we should do something, you know, just the two of us." Mabel said later that day, glancing at Danny.

Danny raised his eyebrows but said nothing.

"That sounds fun, Mabel. What do you want to do?" Dipper asked casually. He hadn't forgotten Danny's warning, but Mabel had been acting fairly normal all day. The only odd thing was that they couldn't get Waddles to come near her.

"Let's go for a walk," Mabel said, gesturing for Dipper to follow her into the woods. She glanced at Danny with a look that said _follow us and you're dead._ Danny's eyes widened but Mabel shook her head very slightly and he gulped and nodded. Whatever had happened to Mabel, she wasn't herself. What could he do?

Dipper had missed the exchange. "Come on then, let's go!" he said, happily oblivious.

Dipper and not-Mabel ran into the woods, leaving Danny standing at the edge with a shocked look on his face. Okay, obviously a ghost was overshadowing Mabel, but she knew about overshadowing, and she should be able to fight it. Was something even bigger at work? What about that demon, Bill? Was this his doing? Had he overshadowed her or possessed her, or was he just mind-controlling her?

Danny's mind was reeling. He had to do something to save Mabel, and Dipper too. Bill probably wanted him away from Danny for a reason. Should he risk following them? Would Bill recognize his presence, even if he was invisible? What would he do if he caught Danny?

After a few minutes of anxious thought, Danny decided that he didn't care what Bill did. He transformed into Phantom and flew, invisible and intangible, straight on the path the twins had taken.


	18. Chapter 18

_No! No! No!_ Mabel tried to scream but it was useless. She was so tired. She had been fighting Bill for hours now. She was aware of what was going on around her, both in the outside world and within her own mind. She knew Bill's basic thoughts and he knew hers.

 _You can't!_ Her consciousness yelled at him. _Don't hurt him! Leave Dipper alone!_

 **You agreed to this, Shooting Star. Now shut up and let me get on with it.** Bill's voice answered back, though no sound was coming out of Mabel's physical mouth.

"Is this far enough?" Dipper asked, slightly behind MaBill.

"Almost," came the reply out of their mouth.

 _No! Turn around, Dipper! Go back!_ Mabel tried to scream yet again but it was no use. She didn't know exactly what Bill wanted with Dipper but she knew it couldn't be good. Before they had left the Shack, Bill had grabbed a knife and hid it in her sweater. He also had hidden one of Danny's thermoses in the woods, which Mabel suspected also wasn't good.

"Why do we have to go so far?" Dipper said, panting.

"It's a secret!" MaBill said with the faintest trace of sinister laughter. Dipper was too tired to notice. "Okay, we're here! Now wait just a minute, I have to set it up."

"Set it up?" Dipper asked, confused.

MaBill just smiled and walked a little farther into the woods, just so Dipper couldn't see where they went.

* * *

Danny zoomed toward where he heard MaBill's distorted voice. He was almost there. He caught sight of Dipper, and, staying invisible, drifted forward. He passed into a clearing where MaBill was standing completely still, their back to him. He got ready to fire an ecto ray at them, but just before he shot, MaBill spoke.

"I knew you wouldn't be able to stay away, Deadman." They turned around, holding their arms behind their back.

Danny was so shocked that he turned visible again. He opened his mouth to retort, but MaBill cut him off.

"Listen, I can't have you interfering with my plans. I could easily defeat you, but frankly I don't have the time. This is much easier. See ya, Deadman."

Before Danny could ask what MaBill meant, he saw a blue glow in their hands. A beam of light shot out at him and he found himself being sucked into the Fenton Thermos before he could fight. He didn't even have time to scream.

* * *

"Okay, Dipper, you can come in now!" MaBill called. Dipper came crashing into the clearing in response, looking slightly worried now.

"Mabel, is everything alright? I thought I heard something…."

"Everything's fine, Dipper. It's all coming together perfectly," MaBill reached inside their sweater, slowly pulling something out of the sleeve.

Dipper was even more worried by this. Mabel had never acted so… so sinister before…. And suddenly everything clicked as he looked into the eyes of the person who should be his sister. He stumbled back as he recognized the slit pupils- it was Bill!

MaBill laughed as Dipper fell to the ground. No more pretending, then. "Finally figured it out, eh Pine Tree?"

Dipper's eyes grew wide as he saw what MaBill was holding. It was a knife.

"Are you g-going t-to kill m-me?" Dipper stammered, too frightened to move.

MaBill shook their head, grinning evilly. Dipper saw, as if in slow motion, Bill move Mabel's hand up to her throat, the knife positioned to slit it in one move.

Dipper froze.

"Give me the journal, Pine Tree. Give it to me now, or she dies."


	19. Chapter 19

Skulker soared over the junkyard. His radar indicated that one of the humans he needed was somewhere inside. He pulled up the case files on this particular human. According to his information, the human should be in the ramshackle pile of metal below him. Skulker landed next to the pile of junk, scanning carefully for his prey.

"YE-HAW!" A ragged old man jumped out from behind the twisted heaps of trash, flying into Skulker's face.

"What the-?!" Skulker yelled, as the man climbed onto his head.

"Well, lookee here!" The man called. His long white beard dangled into Skulker's eyes, obscuring his vision. "Seems I've got myself a brand-new robot!" He spat off to the side, somehow getting it to land in a spittoon over ten feet away.

"What? Get off me, human!" Skulker said, stumbling around and trying to get the crazy old man off his head.

"Wh-hee-hee-hee! Hoo-yeah!" The man yelled as he rode Skulker like a bucking bronco.

"Arrgh!" Skulker said as he ripped the man off his head. The man's eyes stared in opposite directions as he continued to writhe in Skulker's grip, but not as if he were trying to break free. It was more like he were doing some sort of jig.

"Apparently I need you, stange human," Skulker said in resigned confusion. He pulled out a small cube from a compartment of his suit and it sucked the old man inside.

That left only three more targets. Three particularly difficult targets. The twins were going to be a problem if they were still hanging around that ghost child, but Skulker thought if he could get the jump on him he might be able to capture them without too much trouble. The third, however, was a human about whom he had no information whatsoever. He couldn't get a reading for him in any location in Gravity Falls, even though he should be registering on Skulker's instruments the way the others had. It was as if he weren't in Gravity Falls at all. Perhaps not even in this reality.


	20. Chapter 20

Dipper stared, frozen, at the knife held to Mabel's throat.

"Now, Pine Tree!" MaBill said harshly.

"I- I- Mabel-"

"Last chance!" MaBIll sneered, pressing the knife ever so slightly closer to Mabel's neck. A small bead of blood appeared at the edge of the blade.

"Okay!" Dipper said frantically, "I'll give you the journal!" He slipped off his backpack, his hand shaking. He slowly unzipped the main pocket, reaching inside with fumbling fingers. As he lifted the precious book out of the bag, he looked up.

MaBill was staring at the book greedily, the knife now lowered. As Dipper locked eyes with the thing that had possessed his sister, he saw a flicker. For just a second, the slit pupils that came with Bill's influence disappeared, and Mabel's familiar brown eyes looked back at him. She glanced to the side, staring at a bush off to Dipper's right. He followed her gaze, and saw something shiny blinking through the leaves.

Dipper suddenly understood. He jerked the hand holding the journal, throwing it like a frisbee off to his left.

"Hey, what-?" Bill, back in control, used Mabel's body to sprint towards where Dipper had flung the journal. At the same moment, Dipper dove towards the thermos hidden in the bushes. Thankfully, Danny had shown Dipper exactly how to use it. Dipper grabbed it and pushed the release button.

Danny, as Phantom, sprung out of the little metal container, and with a quick glance at the situation, flew straight at MaBill.

Danny collided with Mabel's body just before Bill could grab the journal. He seized them and kept flying in that direction as fast as he could, with a backward look at Dipper.

Dipper followed, running as fast as he could through the underbrush. He knew Danny could handle himself, but Mabel…. If she ended up hurt, it would be his fault. Dipper pushed himself to go even faster. He thought he knew where Danny was going, a place in the woods Dipper had shown him the previous day. It was far away from any monster's lair, but still out of sight from the Shack. A perfect place to practice.

Or to battle.

Dipper arrived in the clearing just in time to see MaBill rise to their feet. Danny was standing in front of them in a stance that showed he meant business.

"Let her go, Cipher." Danny said, with more authority than Dipper had ever heard him speak with before.

MaBill laughed coldly. "What power do you have over me, Deadman? I play by my own rules."

Danny shot two ectoblasts to either side of MaBill, each of which grazed a sleeve of their sweater.

MaBill didn't even try to dodge the blasts. They laughed again. "You want to risk hurting the girl, Deadman? I don't think Pine Tree would be very happy if you killed his sister just to get rid of me!"

Dipper froze. Bill was right. Danny couldn't fight the way he normally did without seriously injuring Mabel. But how else could they weaken Bill enough to get him out of her?

Dipper thought about when he had been possessed. It had taken a lot to get Bill out of him. Over 48 hours with no sleep, constant bodily harm, and intensive tickling. Obviously they didn't have the time to do all that to Mabel, nor did he particularly want to.

But this was different. Mabel was still in there. Maybe Bill was weaker because of that? For a second earlier, they had flickered. Dipper had seen Mabel in there, still fighting.

Danny was thinking along the same lines. This looked more like an overshadowing than a possession, and he could deal with an overshadowing. But they still needed to weaken Bill before he could push such a powerful entity out of Mabel's body.

Danny looked back at Dipper, hoping he had an idea. At that moment, MaBill seized their chance to run past the two boys. They sprinted back the way they had come, towards the place where the journal still lay in the grass.

Danny and Dipper both turned and started after them. Danny grabbed Dipper and shot towards MaBill as fast as he could, blocking their path to the book.

"Thanks for the lift," Dipper said, though shaking a bit from the sudden flight.

"I can't do this alone," Danny replied. "Gonna need your help."

MaBill scoffed. "Even the two of you combined can't defeat me! I am a being of pure energy!"

"In Mabel's body," Dipper retorted. "Remember how fragile us humans are?" Maybe if he could get close enough….

"So you'd hurt her to get to me? Some sibling you are." MaBill said. "She had to hurt you to get me out of you, remember? Maybe you two really are as bad as your uncles."

That was it! Dipper was so consumed in thought that he didn't pay attention to the last thing BIll had said. Bill didn't know! Or at least, he didn't understand. He thought that Mabel had actually been torturing him when she tickled him.

"Hold them down!" Dipper yelled, lunging at MaBill. Danny sped past him and pinned MaBill to the ground in one swift motion.

Dipper grabbed at MaBill's stomach, twitching his fingers expertly.

Bill screamed.

Dipper grinned. Tickling had worked once, and it would again. He continued to tickle them with all his ferocity, something usually saved for late-night tickle fights with Mabel. He knew all her weaknesses, just as she knew his.

"He's weak!" Dipper said triumphantly. "But I don't know how to get him out-"

"Leave that to me!" Danny said, jumping off MaBill and pushing Dipper backwards.

MaBill staggered to their feet, holding their side. "It's not gonna work, Deadman. I'm more powerful than you- I'm more powerful than anything!" They sneered.

Danny crouched down, a look of determination on his face. Then he lunged at MaBill, hands outstretched.

Dipper watched, eyes wide, as Danny went into Mabel's body. She dropped to the ground as her body went into convulsions. Dipper ran to her in fear, wanting to help but not knowing what to do. Her body heaved on the ground. Was this normal?!

Suddenly, Danny came shooting back out of Mabel, dragging Bill with him.

Mabel gasped and her eyes flew open. Dipper gasped too as he saw her normalized pupils.

"Get off me!" Bill said, struggling with Danny in midair. "I'll show you, you little-"

Danny was grappling with Bill, trying to keep him in one spot. "Dipper, the thermos!" Danny said.

"What?" Dipper asked, looking up.

"The thermos!" Danny shouted. "Fire up the thermos!"

"Oh!" Dipper ran towards where he had dropped the thermos in the underbrush and turned around, taking the cap off.

Danny released Bill at that very second and flew to the side as Bill turned towards Dipper. Dipper saw the angry red flash in Bill's eye before the blue light washed over him, sucking him towards the open thermos.

"No! This isn't possible! I'm going to get you for this, Pine Tree!" Bill screamed as he disappeared inside it. Dipper capped the little metal cylinder with a smirk.


	21. Chapter 21

Mabel ran over to Dipper and mauled him with a hug. "You saved me! Oh, Dipper, I was so scared!"

Danny floated down to the ground and transformed back into his human self. "Nice job, Dipper."

Dipper grinned and squeezed Mabel back. "I was so worried, Mabel! Why did you make a deal with Bill?"

Mabel hung her head. "He tricked me. I just wanted to be included. I mean, you two were having so much fun and I was just kind of in the background…"

Dipper and Danny exchanged guilty looks.

"Look, I'm sorry Mabel. We didn't mean to exclude you…" Dipper looked down, unable to meet her eyes.

"It's okay Dipper. I get that you were excited. But I feel like we've kinda been growing apart lately, and I don't want to." Mabel rubbed one of her arms. "I know I shouldn't have made that deal with Bill. I was just so desperate…"

Dipper still couldn't meet her eyes, but Danny smiled. "Sounds kind of like me and my sister. We were really close when we were little, but we grew apart for a while and I couldn't even bring myself to tell her about Phantom when that happened. Since then, though, she's been really supportive and helpful, even if we do argue a lot." He laughed. "We're still really close, even though she's in college now." He knelt down beside the twins. "It just takes some effort."

Dipper held out his arms to Mabel. "Awkward sibling hug?"

Mabel grinned. "Awkward sibling hug." They embraced each other.  
"Pat, pat." They said together as each patted the other on the back.

Danny exploded into laughter. "That's awesome! I've got to use that with Jazz sometime!"

Dipper and Mabel let go of each other and laughed too.

"Let's get back to the Shack," Dipper said and started walking.

"I'm just glad everything is over!" Mabel said as they emerged from the trees.

"I'm not so sure about that…" Danny said, pointing to the Shack. Its windows were all dark, even though night had fallen half an hour ago.

"Maybe Grunkle Stan just went to sleep early tonight?" Mabel suggested, but without any real conviction in her voice.

"But it's not that late," Dipper said nervously as they approached the front door. "Wendy and Soos should still be here."

They opened the door to the Shack slowly, wincing at the loud creak it made. Dipper made to tiptoe into the house, but Danny held him back. "Wait a minute," Danny transformed into Phantom and phased into the house, invisibly scouting all the rooms to see what might be lurking there.

"I couldn't find anything," he said, reappearing outside with the twins. "It looks safe, but no one's in there."

"But Stan never leaves at this time of night…" Mabel said, starting to sound scared. "Did something happen to him?"

"That would be me." An ominous voice echoed from behind the trio. They all turned, Danny already charging an ectoblast in his hands.

Skulker stepped out of the shadows, holding a gun-like device pointed straight at the twins.

Danny stepped protectively in front of them. "What do you want, Skulker?"

"I've already told you, ghost boy. The Council has ordered me to capture ten specific humans in order to prevent a catastrophe. I need these two children, and any information they have regarding the last human." Skulker held up his weapon threateningly.

"No way, Skulker. You're not taking the kids or anyone else." Danny threw a warning blast to Skulker's left, causing him to jump back a few paces.

"Not even you can go against the Council, child." Skulker said. "They rule over the entire Ghost Zone. Even you must obey them."

"Then at least tell me why you need these people!" Danny said. Dipper and Mabel looked at each other in concern behind his back.

"You'll have to take that up with the council. I am only tasked with retrieving the humans." Skulker stepped forward and shot a glowing green net at the twins. Danny didn't manage to blast it out of the way in time, and both Dipper and Mabel were ensnared.

"Stop!" Danny said. "Look, Skulker, I'll talk to the council, but I demand that these two stay free until we come to some conclusion." He held his hands up in a gesture of peace.

Skulker tipped his head to one side, then replied, "Fine. You are in charge of the human children. I will lead you to the council."

Danny freed Dipper and Mabel from the net. "What's going to happen?" Mabel asked, frightened.

"I don't know," Danny said.

"Does he have Stan and the others?" Dipper asked.

"Yes, he does. But don't worry. I won't let anything happen to any of you."


	22. Chapter 22

Skulker lead Danny and the twins to a natural ghost portal hidden deep in a cavern. Dipper's eyes went wide when he saw the otherworldly swirl of green. "Is that-?"

"A portal to the Ghost Zone." Danny said. "Sometimes they appear naturally in your world. I'm honestly not surprised there's one here in Gravity Falls." He turned to Skulker. "How stable is it?"

"As stable as natural portals can be," Skulker replied. "There is something about this place that keeps it open."

"Figures." Danny looked at the twins. "Okay, it's going to get a little weird in there, but stick close to me and you'll be fine." He picked up each of them in one arm and flew straight into the portal.

Dipper closed his eyes as they entered the Ghost Zone. The air was cooler in here, and felt a little bit sticky. Dipper blinked his eyes open again and gasped. They were soaring around a sort of greenish Twilight Zone. There was no terrain at all, just floating objects and doors in random places.

"Which way, Skulker?" Danny asked.

Skulker sped up, going past them. "Just follow me, whelp."

Danny rolled his eyes and sped up too. Dipper couldn't help gazing around in wonder at this strange new world. He caught Mabel's eye and they shared a look of amazement.

"And I thought Gravity Falls was weird…" Dipper muttered to himself.

After a few minutes, they reached a sort of building. Danny landed on the sparse ground outside of it and put the twins down.

"The Ghost Council awaits inside," Skulker said. "Come."

Skulker led the way through the large double doors, with Danny and the twins right behind him. Dipper gasped as they entered the room. It was huge and circular, with screens showing the goings-on of the real world. The strangest things, however, were the inhabitants. Dipper stared at the thousands of identical ghosts in seats lining the room. The were green, with one eye and long robes. They looked like Mike Wazowski, but taller.

"The ghost child wishes to confer with the council," Skulker said formally, gesturing to Danny and moving aside.

"Ah, yes. Danny Phantom." Dipper caught sight of a ghost in the very middle of the chamber. This one was old looking, with blue skin and a scar across one of his red eyes. He wore a purple cloak and held a staff with a clock on it. He looked intimidating, but somehow he didn't seem malicious.

"Hey, Clockwork," Danny said, addressing this ghost.

"Ah!" One of the one-eyed ghosts spoke up before Danny could continue. "You have brought the final humans we need."

"What? No!" Danny said, moving protectively in front of the twins. "I'm here to tell you that you won't be taking them."

Clockwork smiled slightly, but Dipper was the only one who saw. He had been watching Clockwork ever since Danny had spoken to him because he kept changing ages. He went from an old man to a child to middle aged, but as this did not seem to bother anyone else Dipper said nothing about it.

Dipper shook himself and focused on Danny and the rest of the Council. They were glaring at each other.

"This is not your decision, child," A one-eyed ghost said. "We have decreed that we need ten specific humans to prevent the end of reality."

"Woah, woah, woah, the end of reality?" Danny exclaimed. "Who said anything about that?"

"We Observants have seen what is coming to the human world. Destruction and chaos will reign very soon unless we take steps to prevent it. We must-"

Dipper couldn't stay silent any longer. "Wait, how can you know all this? And why do you care about what happens to our world?"

The Observant looked at him sternly. "It is the Council's responsibility to make sure that the Ghost Zone is safe. And as our world is the mirror to yours, the destruction of the Earth would mean the destruction of the Ghost Zone. We do not take this lightly."

"But what about us?" Mabel asked, sounding both scared and indignant. "I mean, I'm all for saving the world, but why do you need us specifically?"

"Because the ancient prophecy foretold the ten symbols of the zodiac needed to defeat the Demon. You are the Shooting Star, are you not? And your brother, the Pine Tree?"

Mabel took a step back, looking shocked.

"Are you talking about Bill?" Dipper asked quickly.

"The demon is known by many names. But yes, we speak of the Cipher."

Dipper, Mabel and Danny looked at each other, confused.

"Council!" Skulker said, speaking up. "I must tell you, the Six-Fingered Hand still eludes me. He does not seem to be in their reality."

The Observants looked at each other in concern. "Are you sure?"

"Yes." Skulker said gravely.

The Observants began to murmur among shot a look at Danny, who seemed to understand something.

"So, you're saying that you're trying to defeat Bill?" Danny interrupted their musings, a slight smile twisting his lips.

Dipper caught on. "Because if you are…"

The Observants stopped talking abruptly, staring at Danny and the twins. "Do you have information on the demon?" The head Observant asked.

Mabel laughed outright. "We have him!" She said.

"You what?" Many Observants looked at each other, astonished.

"We captured Bill Cipher. He's in here," Dipper said, pulling the thermos out of his backpack to general disbelief.

Danny smiled and gave the Observants a sly look. "You shouldn't underestimate humans, you know."

The Observants were silent, staring at the trio. Clockwork decided to step up.

"Well, as the demon is defeated, it seems we no longer need the zodiac. Skulker, you will return the humans to their homes, please."

Skulker nodded stiffly, glared at Danny, and flew off.

Clockwork held a hand out to Dipper. "If you will give me the thermos, child."

Dipper looked nervously at Danny, who gave him a reassuring nod. Dipper handed over the thermos.

"The demon will be confined to his own dimension, but that does not mean he cannot return. You must be diligent. He can only enter your world if he is summoned, so you must be sure not to let that happen."

Dipper and Mabel nodded. "Only a few people know how to summon him," Mabel said. "And they're all either in jail or smart enough to not do it."

Dipper laughed. "Yeah, don't worry."

Clockwork smiled. "Then you may return home, children. Thank you."


	23. Chapter 23

Danny put the twins down on the rocky ground outside the ghost portal and changed back to human.

"Well, that worked out nicely," he said, stretching as the three of them walked out of the cavern and into the sunshine.

"I can't believe all the fuss was about Bill," Mabel said with a little laugh.

"Yeah, I thought he was _our_ problem," Dipper replied. "Who knew ghosts were so meddlesome?"

"Uh, me!" Danny said teasingly.

They laughed and joked as they walked back towards the Shack, though Dipper noticed that Danny was rather quieter than usual.

"What's up?" Dipper asked him as they approached the end of the woods.

"Hmm?" Danny looked at him and shook his head a little. "Sorry, just thinking." He looked down, then out at the Shack that was emerging through the trees. "I mean, now that Bill is gone I don't really have any reason to stay here…"

"What?!" Both twins exclaimed.

"You're leaving?" Mabel asked.

"But we just got to know you!" Dipper said indignantly.

Danny smiled sadly. "The whole reason I came to Gravity Falls was to find out what Bill was up to and stop it. Now that he's taken care of, I kinda have to go back."

"Can't you stay here for a little longer?" Mabel pleaded.

"I'll stay at least until tomorrow. But once all the ghosts realize Bill's out of the way they'll be on the rampage again back home. It's still my job to protect Amity Park."

Dipper looked down, disappointed, but Mabel spoke up.

"Well, then I demand that you give us your number!" She said. "No way am I going to let you disappear!"

In spite of himself, Dipper snorted with laughter. "No pun intended," he added.

Danny laughed. "Fair enough. And you guys should come visit me in Amity Park sometime. You could help me fight!"

"Yeah!" Dipper said, excited.

The three of them walked back to the Shack, laughing and talking about further adventures to come, and planning a possible trip to Amity Park. Dipper grinned to himself. Gravity Falls might be chaotic, but nothing that happened in Amity Park could possibly top what happened here.

Could it?

THE END


End file.
